WO2012090532A1 - Photocurable resin composition, dry film and cured object obtained therefrom, and printed wiring board obtained using these - Google Patents

Abstract

The purpose of the present invention is to provide a photocurable and alkaline-solution-developable resin composition which, even when containing a filler incorporated in a large quantity, gives a solder resist that has satisfactory handleability and can be inhibited from cracking or peeling off during thermal shock cycles. The composition comprises a carboxylated oligomer, a polymeric binder that has a higher molecular weight than the carboxylated oligomer, a photopolymerization initiator, a photopolymerizable monomer, and a filler, wherein the content of the filler is 30-60 mass% with respect to the total amount of the nonvolatile components of the composition. A thermoplastic resin is suitable as the polymeric binder, and the thermoplastic resin preferably is in the state of having been dissolved in a solvent so that the thermoplastic-resin solution has a solid content of 10-50 wt.%. The photocurable resin composition or a dry film obtained therefrom is advantageously applicable to the formation of a cured film such as the solder resist of a printed wiring board.

Description

Photocurable resin composition, dry film and cured product thereof, and printed wiring board using them

The present invention relates to a photocurable resin composition used as a solder resist of a printed wiring board, a dry film and a cured product thereof, and a printed wiring board using them.

In recent years, solder resists are also required to have improved workability and higher performance in response to the increase in the density of printed wiring boards as electronic devices become lighter, thinner and shorter. Recently, along with the downsizing, lightening, and high performance of electronic devices, downsizing of semiconductor packages and increasing the number of pins have been put into practical use, and mass production is progressing. In response to this high density, BGA (ball grid array), CSP (chip) instead of IC packages called QFP (quad flat pack package), SOP (small outline package), etc. An IC package called “Scale Package” has appeared. As a solder resist used for such a package substrate or an in-vehicle printed wiring board, various photocurable resin compositions have been conventionally proposed (for example, see Patent Document 1).

High insulation reliability is required for an insulating material such as a solder resist. Therefore, PCT (pressure cooker test) resistance, which is also called moisture heat resistance, is particularly required. On the other hand, from the viewpoint of productivity, a solder resist is also required to have reactivity with ultraviolet rays used for patterning, that is, high exposure sensitivity.

However, the conventional liquid development type solder resist still has room for improvement with respect to the above required characteristics. Furthermore, the conventional liquid development type solder resist has a problem that moisture absorbed inside the package during reflowing due to moisture absorption of the solder resist during package mounting causes boiling of the solder resist film inside the package and its surroundings. is there. Further, in a package with a solder resist, when the IC chip is sealed or when the IC is driven, heat is applied to the substrate and the solder resist, and cracks and peeling are likely to occur due to the difference in expansion coefficient between the substrate and the solder resist. .

In response to such technical problems, there is an attempt to add a large amount of filler to the photosensitive resin composition for solder resist (see Patent Document 2). The present inventors have confirmed that when the filler is added in a large amount to the photosensitive resin composition, the apparent heat resistance and water absorption rate of the resulting coating film are reduced. In many cases, the filler itself is grounded to the adherend, and the fluidity of the composition is remarkably deteriorated in addition to the problem that the adhesion of the coating film is lowered. In particular, when blended with a photopolymerizable monomer, it becomes a dilatancy fluid and cannot be stirred or even coated. In addition, with a negative photosensitive resin composition such as a solder resist, there is a problem that sufficient resolution cannot be obtained for a small-diameter opening due to the filler, and the opening is considerably closed due to light halation. there were.

Japanese Patent Laid-Open No. 61-243869 JP 2000-181058 A

Therefore, the object of the present invention is that even if a large amount of filler is blended, the adhesiveness and fluidity of the composition are not lowered, it can be easily applied to the substrate, and the linear expansion coefficient of the solder resist is lowered. It is in providing the photocurable resin composition which can suppress generation | occurrence | production and the peeling of the crack of the soldering resist which arises at the time of a thermal cycle by making it.
In addition, it improves the characteristics such as the resolution required for conventional solder resist of printed wiring boards and interlayer insulation materials of multilayer wiring boards, electroless gold plating resistance, PCT resistance resulting from adhesion, and In particular, a photocurable resin composition capable of forming a cured film having excellent characteristics required for IC packages, capable of responding to high density and surface mounting of printed wiring boards, and capable of forming small-diameter openings by alkali development. Is to provide.
Furthermore, a dry film and a cured product excellent in various properties as described above obtained by using such a photocurable resin composition, and a cured film such as a solder resist is formed by the dry film and the cured product. It is to provide a printed wiring board.

In order to achieve the above object, according to the present invention, there is provided a composition comprising a carboxyl group-containing oligomer, a polymer binder having a molecular weight larger than that of the carboxyl group-containing oligomer, a photopolymerization initiator, a photopolymerizable monomer, and a filler. Thus, there is provided a photocurable resin composition that can be developed with an alkaline solution, characterized in that the content of the filler is 30 to 60% by mass of the total amount of nonvolatile components of the composition.
According to a preferred embodiment, the polymer binder is a thermoplastic resin, preferably a thermoplastic resin solution having a solid content of 10 to 50 wt% dissolved in a solvent. According to another preferred embodiment, the filler contains Ba or Mg and / or Al.

Further, according to the present invention, the photocurable resin composition obtained by applying and drying the photocurable resin composition on a carrier film, the photocurable resin composition or the dry film can be converted into active energy. There are also provided a cured product obtained by photocuring by irradiation of a line, particularly a cured product obtained by photocuring on copper, and a cured product obtained by photocuring in a pattern. In one aspect, a dry film consists of a dried layer of a plurality of photocurable resin compositions, and at least one layer is formed from the photocurable resin composition of the present invention.
Furthermore, according to the present invention, the print is characterized by having a cured film obtained by photocuring the photocurable resin composition or the dry film into a pattern by irradiation with active energy rays, and preferably further thermosetting. A wiring board is also provided.

The photocurable resin composition of the present invention has a linear expansion coefficient of 15 to 35 × 10 − when the filler content is 30 to 60% by mass of the total amount of nonvolatile components of the composition. It can be adjusted to a range of 6 / K (hereinafter abbreviated as ppm), and the occurrence of solder resist cracks can be reduced by matching or approaching the linear expansion coefficient with the base. Furthermore, by adding a binder having a higher molecular weight than that of the carboxyl group-containing oligomer, the adhesiveness of the composition, which is a problem that occurs when a large amount of filler is blended, reduced fluidity, reduced film formability, Problems such as handling cracks are solved, and when the cured product is used, for example, in a printed wiring board or a semiconductor package, excellent resolution and PCT resistance resulting from adhesion are obtained, and high reliability. Can be obtained.

The photocurable resin composition developable with the alkaline solution of the present invention (hereinafter also referred to as a photocurable resin composition) includes a carboxyl group-containing oligomer, a polymer binder having a higher molecular weight than the carboxyl group-containing oligomer, and photopolymerization. A composition comprising an initiator, a photopolymerizable monomer and a filler, wherein the filler content is 30 to 60% by mass of the total amount of nonvolatile components of the composition.
Hereinafter, each component of the photocurable resin composition of the present invention will be described in detail.

The photocurable resin composition of the present invention can impart alkali developability by using a carboxyl group-containing oligomer. In the present specification, the term “oligomer” should be understood to be used to make it easy to distinguish the molecular weight from the polymer binder. As the carboxyl group-containing oligomer, various conventionally known carboxyl group-containing resins or prepolymers having a carboxyl group in the molecule can be used. In particular, a carboxyl group-containing photosensitive resin or a carboxyl group-containing photosensitive prepolymer having an ethylenically unsaturated double bond in the molecule is more preferable in terms of photocurability and development resistance. And the unsaturated double bond is preferably derived from acrylic acid, methacrylic acid or derivatives thereof. When only a carboxyl group-containing resin or prepolymer having no ethylenically unsaturated double bond is used, in order to make the composition photocurable, a plurality of ethylenically unsaturated groups are contained in the molecule described later. It is necessary to use a compound having a photopolymerizable monomer in combination.
As specific examples of the carboxyl group-containing oligomer, oligomers listed below can be suitably used.

(1) A carboxyl group-containing oligomer obtained by copolymerization of an unsaturated carboxylic acid such as (meth) acrylic acid and an unsaturated group-containing compound such as styrene, α-methylstyrene, lower alkyl (meth) acrylate, and isobutylene.

(2) Diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates; carboxyl group-containing dialcohol compounds such as dimethylolpropionic acid and dimethylolbutanoic acid, polycarbonate polyols, and polyethers A carboxyl group-containing urethane resin by a polyaddition reaction of a diol compound such as a polyol, a polyester-based polyol, a polyolefin-based polyol, an acrylic polyol, a bisphenol A-based alkylene oxide adduct diol, a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group.

(3) Diisocyanate and bifunctional epoxy resin such as bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bixylenol type epoxy resin, biphenol type epoxy resin ( A carboxyl group-containing photosensitive urethane resin obtained by a polyaddition reaction of (meth) acrylate or a partially acid anhydride-modified product thereof, a carboxyl group-containing dialcohol compound, and a diol compound.

(4) During the synthesis of the resin of (2) or (3), a compound having one hydroxyl group and one or more (meth) acryl groups in a molecule such as hydroxyalkyl (meth) acrylate is added, and the terminal ( (Meth) acrylic carboxyl group-containing photosensitive urethane resin.

(5) During the synthesis of the resin of the above (2) or (3), one isocyanate group and one or more (meth) acryl groups are introduced into the molecule, such as an equimolar reaction product of isophorone diisocyanate and pentaerythritol triacrylate. A carboxyl group-containing photosensitive urethane resin obtained by adding a compound having a terminal (meth) acrylate.

(6) (Meth) acrylic acid is reacted with a bifunctional or higher polyfunctional (solid) epoxy resin as described later, and phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride are added to the hydroxyl group present in the side chain. A carboxyl group-containing photosensitive oligomer to which a dibasic acid anhydride such as

(7) A polyfunctional epoxy resin obtained by epoxidizing a hydroxyl group of a bifunctional (solid) epoxy resin as described later with epichlorohydrin is reacted with (meth) acrylic acid, and a dibasic acid anhydride is added to the resulting hydroxyl group. An added carboxyl group-containing photosensitive oligomer.

(8) A carboxyl group-containing polyester obtained by reacting a dicarboxylic acid such as adipic acid, phthalic acid or hexahydrophthalic acid with a bifunctional oxetane resin as described later, and adding a dibasic acid anhydride to the resulting primary hydroxyl group. Oligomer.

(9) Reaction product obtained by reacting a compound obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide with an unsaturated group-containing monocarboxylic acid. Carboxyl group-containing photosensitive oligomer obtained by reacting polybasic acid anhydrides such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like.

(10) Obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with a reaction product obtained by reacting a cyclic carbonate compound such as ethylene carbonate or propylene carbonate with an unsaturated group-containing monocarboxylic acid. A carboxyl group-containing photosensitive oligomer obtained by reacting a reaction product with a polybasic acid anhydride.

(11) A carboxyl group-containing photosensitive oligomer obtained by adding a compound having one epoxy group and one or more (meth) acryl groups in one molecule to the resins (1) to (10).
In addition, in this specification, (meth) acrylate is a term that collectively refers to acrylate, methacrylate, and mixtures thereof, and the same applies to other similar expressions.

Since the carboxyl group-containing oligomer as described above has a large number of carboxyl groups in the side chain of the backbone polymer, development with a dilute alkaline aqueous solution becomes possible.
The acid value of the carboxyl group-containing oligomer is suitably in the range of 40 to 200 mgKOH / g, more preferably in the range of 45 to 120 mgKOH / g. When the acid value of the carboxyl group-containing oligomer is less than 40 mgKOH / g, alkali development becomes difficult. On the other hand, if it exceeds 200 mgKOH / g, dissolution of the exposed portion by the developer proceeds, and the line may become thinner than necessary. Depending on the case, the exposed portion and the unexposed portion are not distinguished from each other by dissolution and peeling with a developer, which makes it difficult to draw a normal resist pattern.

The weight average molecular weight of the carboxyl group-containing oligomer varies depending on the resin skeleton, but is generally within the range of 2,000 to 150,000, more preferably 5,000 to 100,000. Although it is necessary to use a carboxyl group-containing oligomer having a weight average molecular weight lower than that of the polymer binder to be used, a particularly preferable weight average molecular weight is 5000 to 35,000. If the weight average molecular weight is less than 2,000, the tack-free performance of the coating film may be inferior, the moisture resistance of the coating film after exposure may be poor, the film may be reduced during development, and the resolution may be greatly inferior. On the other hand, when the weight average molecular weight exceeds 150,000, developability is remarkably deteriorated. Moreover, when larger than the polymeric binder mentioned later, the improvement of the brittleness of the target coating film cannot be performed.

The compounding amount of such a carboxyl group-containing oligomer is 10 to 60% by mass, preferably 20 to 50% by mass of the total composition. When the amount of the carboxyl group-containing oligomer is less than the above range, the film strength is lowered, which is not preferable. On the other hand, when the amount is larger than the above range, the viscosity of the composition is increased or the coating property is lowered, which is not preferable.

These carboxyl group-containing oligomers can be used without being limited to those listed above, and can be used singly or in combination. In particular, among the carboxyl group-containing oligomers, resins having an aromatic ring are preferable because they have a high refractive index and excellent resolution, and those having a biphenyl novolak structure not only have resolution but also PCT. It is preferable because it is excellent in resistance and crack resistance. In addition, carboxyl group-containing oligomers using a phenol compound as a starting material, such as carboxyl group-containing photosensitive oligomers (9) and (10), are also preferable because PCT resistance is similarly improved. In general, the increase in the filler component makes it easy for water absorption to occur at the interface between the filler and the resin, whereas those having a biphenyl novolak structure and carboxyl group-containing oligomers such as (9) and (10) Even if the filler component increased, the PCT resistance was very excellent. This is probably because the former has improved hydrophobicity due to the biphenyl novolac structure, and the latter has a carboxyl group-containing photosensitive oligomer (6) and (7) with an epoxy acrylate structure that can form a similar structure. On the other hand, it is considered that the carboxyl group-containing photosensitive oligomers (9) and (10) do not have a hydroxyl group and the hydrophobicity is remarkably improved.

The polymer binder is not particularly limited as long as it is a thermoplastic resin regardless of whether it is reactive or non-reactive. For example, polyphenylene sulfide, polyarylate, polysulfone, polyethersulfone, polyetheretherketone, Thermoplastic resins such as polyetherketone, thermoplastic polyimide, aromatic resin group called phenoxy resin, cellulose derivatives such as ethylcellulose, acetylcellulose, acetylpropylcellulose, acetylbutylcellulose, various acrylates, styrene, vinyl acetate, etc. A polymer obtained by subjecting a vinyl derivative of the above to solution or suspension polymerization can be used. In addition, a binary copolymer, a ternary copolymer, a block copolymer, and the like obtained by polymerization using a monomer having two or more kinds of vinyl groups can also be used. Of these polymers, those derived from cellulose derivatives and block copolymers are particularly preferred. The preferred molecular weight of the polymer binder is 30,000 to 1,500,000 in terms of weight average molecular weight, but should be used if it is determined that the molecular weight is clearly larger than the carboxyl group-containing oligomer used. Can do. For example, when dissolved in the same solvent, the viscosity is higher than that of the carboxyl group-containing oligomer. Furthermore, since the higher the molecular weight, the lower the solubility in the solvent, the lower the solid content when dissolved in the same solvent, especially when the molecular weight is 10 to 50 wt%, the molecular weight is higher than that of the carboxyl group-containing oligomer. Judged to be large. When the solid content is less than 10 wt%, there is a problem that the solvent content increases and a composition cannot be formed. On the other hand, when it exceeds 50 wt%, it may not correspond to a polymer and is not appropriate.

There are several functions of these polymer binders. One is to change the fluidity of the composition. More specifically, when a large amount of filler is added to the carboxyl group-containing oligomer and the photopolymerizable monomer, the photopolymerizable monomer and the filler are particularly unsuitable, and the resulting composition becomes a dilatancy fluid. When the composition becomes dilatancy, it is difficult to stir, print, or coat the composition, and it cannot be used unless it is in a considerably diluted state, and in particular, it is performed at a relatively high viscosity such as screen printing or roll coating. In the case of printing, there is a problem that a required film thickness cannot be secured by one printing. When a polymeric binder was added here, the composition could be transformed into a thixotropic fluid. This is the first material that can be printed and coated. The second effect has been shown to control handling cracks when the composition is coated and dried to a dry film state. This is considered to be due to the effect of holding the filler containing a large amount of the polymer binder. The third effect of adding the polymer binder is that the toughness of the coating film can be increased in the physical properties after curing. This is presumably because the polymer binder is present in an IPN (sea island) state in the photocurable resin matrix. For the above three reasons, only when a polymer binder is added, a composition in which a photopolymerizable monomer and a large amount of filler coexist can be printed and coated, has a low coefficient of linear expansion, and has a tough coating. It is considered that a film can be obtained.

In addition, these polymer binders may have functional groups such as a carboxyl group, a hydroxyl group, and an epoxy group at the terminal and / or side chain. A suitable amount of the carboxyl group is an acid value of 30 mgKOH / g or less.

A suitable blending amount of the polymer binder is 1 part by mass or more with respect to 100 parts by mass of the carboxyl group-containing oligomer. Thus, even if a small amount of the polymer binder is added, the fluidity of the composition can be sufficiently achieved. Furthermore, in order to sufficiently improve the physical properties, a larger amount of polymer binder can be added, but the upper limit is suitably about 30 parts by mass with respect to 100 parts by mass of the carboxyl group-containing oligomer. When the addition amount of the polymer binder is increased, the developability is remarkably deteriorated, and a residue may remain on the circuit formed on the circuit or between the circuits. In such a case, the photocurable resin composition is applied by 2 The composition of the present invention in which a polymer binder is not included or less than 5 parts by weight is applied in the first construction, and then the polymer binder and a large amount of filler are blended. When applied, the problem of poor development is solved. Similarly, when forming a dry film, it is composed of two or more layers, and the layer on the side directly touching the substrate is formed of a composition layer having no polymer binder or a proportion of less than 5 parts by mass, and the like. This layer can be solved by forming a layer with the composition of the present invention containing a large amount of a polymer binder.

Examples of the photopolymerization initiator used in the photocurable resin composition of the present invention include an oxime ester photopolymerization initiator having an oxime ester group, an α-aminoacetophenone photopolymerization initiator, and an acylphosphine oxide photopolymerization initiator. One or more selected from the group consisting of can be preferably used.

Examples of the oxime ester photopolymerization initiator include CGI-325, Irgacure (registered trademark) OXE01, Irgacure OXE02 manufactured by BASF Japan, N-1919, NCI-831 manufactured by ADEKA, and the like as commercially available products. Moreover, the photoinitiator which has two oxime ester groups in a molecule | numerator can also be used suitably, Specifically, the oxime ester compound which has a carbazole structure represented with the following general formula is mentioned.

(In the formula, X is a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a phenyl group, a phenyl group (an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms). Group, an amino group, an alkylamino group having an alkyl group having 1 to 8 carbon atoms or a dialkylamino group), a naphthyl group (an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms), And Y and Z are each a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, or a carbon atom having 1 carbon atom), substituted with an alkyl group having a C 1-8 alkyl group or a dialkylamino group. Alkyl groups having 8 to 8 alkoxy groups, halogen groups, phenyl groups, phenyl groups (alkyl groups having 1 to 17 carbon atoms, alkoxy groups having 1 to 8 carbon atoms, amino groups, alkyl groups having 1 to 8 carbon atoms) Or substituted with a dialkylamino group), a naphthyl group (an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, an alkylamino group having an alkyl group having 1 to 8 carbon atoms, or Represents an anthryl group, a pyridyl group, a benzofuryl group, a benzothienyl group, Ar is a bond or alkylene having 1 to 10 carbon atoms, vinylene, phenylene, biphenylene, pyridylene, naphthylene, thiophene , Anthrylene, thienylene, furylene, 2,5-pyrrole-diyl, 4,4′-stilbene-diyl, 4,2′-styrene-diyl, and n is an integer of 0 or 1.)
In particular, in the above general formula, X and Y are each a methyl group or an ethyl group, Z is methyl or phenyl, n is 0, and Ar is a bond, phenylene, naphthylene, thiophene or thienylene. It is preferable.

The blending amount of such an oxime ester photopolymerization initiator is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of the carboxyl group-containing oligomer. When it is less than 0.01 parts by mass, the photocurability on copper is insufficient, the coating film is peeled off, and the coating properties such as chemical resistance are deteriorated. On the other hand, when the amount exceeds 5 parts by mass, light absorption on the surface of the coating film becomes intense, and the deep curability tends to decrease. More preferably, it is 0.5 to 3 parts by mass.

Specific examples of α-aminoacetophenone photopolymerization initiators include 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, N , N-dimethylaminoacetophenone and the like. Examples of commercially available products include Irgacure 907, Irgacure 369, and Irgacure 379 manufactured by BASF Japan.

Specific examples of acylphosphine oxide photopolymerization initiators include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, and bis (2,6-dimethoxy). And benzoyl) -2,4,4-trimethyl-pentylphosphine oxide. Examples of commercially available products include Lucilin TPO manufactured by BASF, Irgacure 819 manufactured by BASF Japan, and the like.

The blending amount of these α-aminoacetophenone photopolymerization initiator and acylphosphine oxide photopolymerization initiator is preferably 0.01 to 15 parts by mass with respect to 100 parts by mass of the carboxyl group-containing oligomer. If it is less than 0.01 parts by mass, the photo-curability on copper is similarly insufficient, the coating film peels off, and the coating properties such as chemical resistance deteriorate. On the other hand, when the amount exceeds 15 parts by mass, the effect of reducing the outgas cannot be obtained, the light absorption on the surface of the coating film becomes intense, and the deep curability tends to decrease. More preferably, it is 0.5 to 10 parts by mass.

Here, as the photopolymerization initiator to be used, the oxime ester initiator is added in a small amount, and outgassing is suppressed, which is effective in terms of PCT resistance and crack resistance. Further, it is particularly preferable to use an acylphosphine oxide photopolymerization initiator in addition to the oxime ester initiator because a shape with good resolution can be obtained.

In addition, examples of the photopolymerization initiator, photoinitiator assistant, and sensitizer that can be suitably used in the photocurable resin composition of the present invention include benzoin compounds, acetophenone compounds, anthraquinone compounds, thioxanthone compounds, ketal compounds, and benzophenones. Compounds, tertiary amine compounds, and xanthone compounds.

Specific examples of the benzoin compound include benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether.

Specific examples of the acetophenone compound include acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, and the like.

Specific examples of the anthraquinone compound include 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 1-chloroanthraquinone and the like.

Specific examples of the thioxanthone compound include 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone, and the like.

Specific examples of the ketal compound include acetophenone dimethyl ketal and benzyl dimethyl ketal.

Specific examples of the benzophenone compound include benzophenone, 4-benzoyldiphenyl sulfide, 4-benzoyl-4′-methyldiphenyl sulfide, 4-benzoyl-4′-ethyldiphenyl sulfide, and 4-benzoyl-4′-propyldiphenyl. And sulfides.

Specific examples of the tertiary amine compound include an ethanolamine compound and a compound having a dialkylaminobenzene structure, such as 4,4′-dimethylaminobenzophenone (Nisso Cure MABP manufactured by Nippon Soda Co., Ltd.), Dialkylaminobenzophenones such as 4′-diethylaminobenzophenone (EAB manufactured by Hodogaya Chemical Co.), 7- (diethylamino) -4-methyl-2H-1-benzopyran-2-one (7- (diethylamino) -4-methylcoumarin), etc. A dialkylamino group-containing coumarin compound, ethyl 4-dimethylaminobenzoate (Kayacure (registered trademark) EPA manufactured by Nippon Kayaku Co., Ltd.), ethyl 2-dimethylaminobenzoate (Quantacure DMB manufactured by International Bio-Synthetics), -Dimethylaminobenzoic acid (n-butoxy) ethyl (Quantacure BEA manufactured by International Bio-Synthetics), p-dimethylaminobenzoic acid isoamylethyl ester (Kayacure DMBI manufactured by Nippon Kayaku Co., Ltd.), 4-dimethylaminobenzoic acid 2 -Ethylhexyl (Esolol 507 manufactured by Van Dyk), 4,4'-diethylaminobenzophenone (EAB manufactured by Hodogaya Chemical Co.), and the like.

Of these, thioxanthone compounds and tertiary amine compounds are preferred. In particular, the inclusion of a thioxanthone compound is preferable from the viewpoint of deep curability. Of these, thioxanthone compounds such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone are preferably included.

The amount of such a thioxanthone compound is preferably 20 parts by mass or less with respect to 100 parts by mass of the carboxyl group-containing oligomer. When the blending amount of the thioxanthone compound exceeds 20 parts by mass, the thick film curability is lowered and the cost of the product is increased. More preferably, it is 10 parts by mass or less.

As the tertiary amine compound, a compound having a dialkylaminobenzene structure is preferable, and among them, a dialkylaminobenzophenone compound, a dialkylamino group-containing coumarin compound having a maximum absorption wavelength of 350 to 450 nm, and ketocoumarins are particularly preferable.

As the dialkylaminobenzophenone compound, 4,4′-diethylaminobenzophenone is preferable because of its low toxicity. The dialkylamino group-containing coumarin compound has a maximum absorption wavelength of 350 to 410 nm in the ultraviolet region, so it is less colored and uses a colored pigment as well as a colorless and transparent photosensitive composition, and reflects the color of the colored pigment itself. It becomes possible to provide a solder resist film. In particular, 7- (diethylamino) -4-methyl-2H-1-benzopyran-2-one is preferred because it exhibits an excellent sensitizing effect on laser light having a wavelength of 400 to 410 nm.

The blending amount of such a tertiary amine compound is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the carboxyl group-containing oligomer. When the compounding amount of the tertiary amine compound is less than 0.1 part by mass, a sufficient sensitizing effect tends not to be obtained. When the amount exceeds 20 parts by mass, light absorption on the surface of the dried solder resist coating film by the tertiary amine compound becomes intense, and the deep curability tends to decrease. More preferably, it is 0.1 to 10 parts by mass.

These photopolymerization initiators, photoinitiator assistants, and sensitizers can be used alone or as a mixture of two or more.
The total amount of such photopolymerization initiator, photoinitiator assistant, and sensitizer is preferably 35 parts by mass or less with respect to 100 parts by mass of the carboxyl group-containing oligomer. When it exceeds 35 parts by mass, the deep curability tends to decrease due to light absorption.

In addition, since these photopolymerization initiators, photoinitiator assistants, and sensitizers absorb a specific wavelength, the sensitivity may be lowered in some cases, and may function as an ultraviolet absorber. However, they are not used only for the purpose of improving the sensitivity of the composition. Absorbs light of a specific wavelength as necessary to improve the photoreactivity of the surface, change the resist line shape and opening to vertical, tapered, reverse taper, and processing accuracy of line width and opening diameter Can be improved.

The photo-curable resin composition of the present invention contains a filler. As a result of detailed examination of the filler content, 30 to 60% by mass of the filler based on the total amount of nonvolatile components is added. Thus, it has been found that PCT resistance and electrical characteristics (HAST resistance) are improved. Furthermore, when the refractive index of the filler is in the range of 1.50 to 1.65, not only PCT resistance and HAST resistance (resistance to the advanced accelerated life test) are excellent, but also good resolution is obtained. It was also found out. The reason why high resolution can be obtained is that the refractive index of the resin having an aromatic ring used for improving PCT resistance and HAST resistance is close to the refractive index of the filler.

Examples of fillers that can be used in the present invention include known and commonly used inorganic fillers such as barium sulfate, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, boehmite, mica powder, and hydrotalcite. it can. According to a preferred embodiment, the filler contains Ba or Mg and / or Al. In particular, the filler containing Ba is barium sulfate (refractive index: 1.65), and the filler containing Mg is talc (refractive index: 1.54-59), magnesium carbonate (refractive index: 1.57-1.60). As fillers containing Al, kaolinite, clay (refractive index: 1.55-1.57), aluminum oxide (refractive index: 1.65), aluminum hydroxide (refractive index: 1.65), boehmite (refractive) Ratio: 1.62-1.65), mica powder (refractive index: 1.59), and filler containing Mg and Al is preferably hydrotalcite (refractive index: 1.50).

The total amount of filler is suitably in the range of 30 to 60% by mass with respect to the total amount of nonvolatile components of the photocurable resin composition. When the filler content is less than 30% by mass, the cured product of the photocurable resin composition does not show a decrease in coefficient of linear expansion, and is not preferable because crack resistance deteriorates. On the other hand, when it exceeds 60% by mass, the viscosity of the composition increases, the coating and moldability deteriorates, and the water absorption also increases, so that the PCT resistance and HAST resistance deteriorate, which is not preferable. Moreover, these fillers can be used individually or in combination of 2 or more types.

It is preferable to add a mercapto compound to the photocurable resin composition of the present invention. It was observed that the addition of mercapto compounds improves PCT resistance and HAST resistance. This may be because the crosslink density was improved by adding a mercapto compound, or the adhesion was improved.

The blending amount of the mercapto compound is suitably 0.01 parts by mass or more and 10.0 parts by mass or less, more preferably 0.05 parts by mass or more and 5 parts by mass with respect to 100 parts by mass of the carboxyl group-containing oligomer. Or less. If it is less than 0.01 part by mass, the improvement in adhesion as an effect of adding a mercapto compound is not confirmed. On the other hand, if it exceeds 10.0 parts by mass, the development failure of the photocurable resin composition and the decrease in the dry management width will be confirmed. This is not preferable because it may cause These mercapto compounds can be used alone or in combination of two or more.

A thermosetting component can be added to the photocurable resin composition of the present invention. It was confirmed that heat resistance was improved by adding a thermosetting component. Examples of thermosetting components used in the present invention include amino resins such as melamine resins, benzoguanamine resins, melamine derivatives, benzoguanamine derivatives, blocked isocyanate compounds, cyclocarbonate compounds, polyfunctional epoxy compounds, polyfunctional oxetane compounds, episulfide resins, bismaleimides. Well-known thermosetting resins such as carbodiimide resins can be used. Particularly preferred is a thermosetting component having a plurality of cyclic ether groups and / or cyclic thioether groups (hereinafter abbreviated as cyclic (thio) ether groups) in the molecule.

Such a thermosetting component having a plurality of cyclic (thio) ether groups in the molecule has either one of the three-, four- or five-membered cyclic (thio) ether groups or a plurality of two types of groups in the molecule. Compound, for example, a compound having a plurality of epoxy groups in the molecule, that is, a polyfunctional epoxy compound, a compound having a plurality of oxetanyl groups in the molecule, that is, a polyfunctional oxetane compound, a compound having a plurality of thioether groups in the molecule That is, an episulfide resin etc. are mentioned.

Examples of the polyfunctional epoxy compound include epoxidized vegetable oils such as Adekasizer O-130P, Adekasizer O-180A, Adekasizer D-32, and Adekasizer D-55 manufactured by ADEKA; jER (registered trademark) manufactured by Mitsubishi Chemical Corporation 828, jER834, jER1001, jER1004, EHPE3150 manufactured by Daicel Chemical Industries, Epicron (registered trademark) 840 manufactured by DIC, Epicron 850, Epicron 1050, Epicron 2055, Epotot (registered trademark) YD manufactured by Nippon Steel Chemical Co., Ltd. -011, YD-013, YD-127, YD-128, D.C. E. R. 317, D.E. E. R. 331, D.D. E. R. 661, D.D. E. R. 664, BASF Japan Araldide 6071, Araldide 6084, Araldide GY250, Araldide GY260, Sumitomo Chemical Co., Ltd. Sumi-Epoxy ESA-011, ESA-014, ELA-115, ELA-128, Asahi Kasei Kogyo Co., Ltd. E. R. 330, A.I. E. R. 331, A.I. E. R. 661, A.I. E. R. Bisphenol A type epoxy resin such as 664 (all trade names); Hydroquinone type epoxy resin such as YDC-1312 (trade name) manufactured by Nippon Steel Chemical Co., Ltd. YSLV-80XY (trade name) manufactured by Nippon Steel Chemical Co., Ltd. Bisphenol type epoxy resins such as YSLV-120TE (trade name) manufactured by Nippon Steel Chemical Co., Ltd .; jERYL903 manufactured by Mitsubishi Chemical Corporation, Epicron 152, Epicron 165 manufactured by DIC, Nippon Steel Chemical Co., Ltd. Epototo YDB-400, YDB-500 manufactured by Dow Chemical Co., Ltd. E. R. 542, Araldide 8011 manufactured by BASF Japan, Sumi-epoxy ESB-400, ESB-700 manufactured by Sumitomo Chemical Co., Ltd. E. R. 711, A.I. E. R. Brominated epoxy resins such as 714 (both trade names); jER152 and jER154 manufactured by Mitsubishi Chemical Corporation, and D.C. E. N. 431, D.D. E. N. 438, Epicron N-730, Epicron N-770, Epicron N-865 manufactured by DIC, Epototo YDCN-701, YDCN-704 manufactured by Nippon Steel Chemical Co., Ltd., Araldide ECN1235, Araldide ECN1273, Araldide ECN1299 manufactured by BASF Japan , Araldide XPY307, Nippon Kayaku Co., Ltd. EPPN (registered trademark) -201, EOCN (registered trademark) -1025, EOCN-1020, EOCN-104S, RE-306, Sumitomo Chemical Co., Ltd. Sumi-epoxy ESCN-195X ESCN-220, manufactured by Asahi Kasei Kogyo Co., Ltd. E. R. Novolak type epoxy resins such as ECN-235 and ECN-299 (both trade names); biphenol novolak type epoxy resins such as NC-3000 and NC-3100 manufactured by Nippon Kayaku; Epicron 830 manufactured by DIC, Mitsubishi Chemical JER807 manufactured by Nippon Steel Chemical Co., Ltd., Epotot YDF-170, YDF-175, YDF-2004 manufactured by Nippon Steel Chemical Co., Ltd., Araldide XPY306 manufactured by BASF Japan Co., Ltd. (all trade names); manufactured by Nippon Steel Chemical Co., Ltd. Hydrogenated bisphenol A type epoxy resin such as Epototo ST-2004, ST-2007, ST-3000 (trade name), etc .; jER604 manufactured by Mitsubishi Chemical Corporation, Epototo YH-434 manufactured by Nippon Steel Chemical Co., Ltd., manufactured by BASF Japan Araldide MY720 from Sumitomo Chemical Co., Ltd. 20 etc. (all trade names) glycidylamine type epoxy resins; Hydantoin type epoxy resins such as Araldide CY-350 (trade name) manufactured by BASF Japan; Celoxide (registered trademark) 2021 manufactured by Daicel Chemical Industries, BASF Japan Alicyclic epoxy resins such as Araldide CY175, CY179, etc. (both are trade names) manufactured by Mitsubishi Chemical Corporation; YL-933 manufactured by Mitsubishi Chemical Corporation; E. N. , EPPN-501, EPPN-502, etc. (all trade names) trihydroxyphenylmethane type epoxy resin; Mitsubishi Chemical Corporation YL-6056, YX-4000, YL-6121 (all trade names), etc. Type or biphenol type epoxy resin or a mixture thereof; Nippon Kayaku EBPS-200, ADEKA EPX-30, DIC EXA-1514 (trade name), etc .; bisphenol S type epoxy resin; Bisphenol A novolac type epoxy resin such as jER157S (trade name); tetraphenylolethane type epoxy resin such as jERYL-931 manufactured by Mitsubishi Chemical Corporation, Araldide 163 manufactured by BASF Japan Co., Ltd. (all trade names); BASF Japan Araldide PT810 (trade name) manufactured by Nissan Chemical Industries Heterocyclic epoxy resins such as TEPIC (registered trademark) manufactured by Nihon Yushi Co., Ltd. Diglycidyl phthalate resins such as Blemmer (registered trademark) DGT manufactured by Nippon Oil &Fats; Tetraglycidyl xylenoyl ethane such as ZX-1063 manufactured by Nippon Steel Chemical Co., Ltd. Resins; Naphthalene group-containing epoxy resins such as Nippon Steel Chemical Co., Ltd. ESN-190, ESN-360, DIC Corporation HP-4032, EXA-4750, EXA-4700; DIC Corporation HP-7200, HP-7200H, etc. Epoxy resin having a dicyclopentadiene skeleton; Epoxy resin copolymerized with glycidyl methacrylate such as CP-50S and CP-50M manufactured by NOF Corporation; Copolymer epoxy resin of cyclohexylmaleimide and glycidyl methacrylate; Epoxy-modified polybutadiene rubber derivative (For example, manufactured by Daicel Chemical Industries B-3600, etc.), CTBN modified epoxy resin (e.g., Nippon Steel Chemical Co. YR-102, YR-450, etc.) and others as mentioned, is not limited thereto. These epoxy resins can be used alone or in combination of two or more. Among these, a novolak type epoxy resin, a bixylenol type epoxy resin, a biphenol type epoxy resin, a biphenol novolak type epoxy resin or a mixture thereof is particularly preferable.

Examples of the polyfunctional oxetane compound include bis [(3-methyl-3-oxetanylmethoxy) methyl] ether, bis [(3-ethyl-3-oxetanylmethoxy) methyl] ether, 1,4-bis [(3- Methyl-3-oxetanylmethoxy) methyl] benzene, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, (3-methyl-3-oxetanyl) methyl acrylate, (3-ethyl-3- In addition to polyfunctional oxetanes such as oxetanyl) methyl acrylate, (3-methyl-3-oxetanyl) methyl methacrylate, (3-ethyl-3-oxetanyl) methyl methacrylate and oligomers or copolymers thereof, oxetane alcohol and novolak resin , Poly (p-hydroxystyrene), cardo type bis Phenol ethers, calixarenes, calix resorcin arenes or etherified products such as the resin having a hydroxyl group such as silsesquioxane and the like. In addition, a copolymer of an unsaturated monomer having an oxetane ring and an alkyl (meth) acrylate is also included.

Examples of the compound having a plurality of cyclic thioether groups in the molecule include bisphenol A type episulfide resin YL7000 manufactured by Mitsubishi Chemical Corporation. Moreover, episulfide resin etc. which replaced the oxygen atom of the epoxy group of the novolak-type epoxy resin with the sulfur atom using the same synthesis method can be used.

The blending amount of the thermosetting component having a plurality of cyclic (thio) ether groups in the molecule is preferably 0.6 to 2.5 equivalents relative to 1 equivalent of the carboxyl group of the carboxyl group-containing oligomer. When the blending amount is less than 0.6, a carboxyl group remains in the solder resist film, and heat resistance, alkali resistance, electrical insulation and the like are lowered. On the other hand, when the amount exceeds 2.5 equivalents, the low molecular weight cyclic (thio) ether group remains in the dry coating film, thereby reducing the strength of the coating film. More preferably, it is 0.8 to 2.0 equivalents.

When using a thermosetting component having a plurality of cyclic (thio) ether groups in the molecule, it is preferable to contain a thermosetting catalyst. Examples of such thermosetting catalysts include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole. Imidazole derivatives such as 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N -Amine compounds such as dimethylbenzylamine and 4-methyl-N, N-dimethylbenzylamine; hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; and phosphorus compounds such as triphenylphosphine. Examples of commercially available products include 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (both trade names of imidazole compounds) manufactured by Shikoku Kasei Kogyo Co., Ltd. and U-CAT (registered by San Apro). Trademarks) 3503N, U-CAT3502T (all are trade names of blocked isocyanate compounds of dimethylamine), DBU, DBN, U-CATSA102, U-CAT5002 (all are bicyclic amidine compounds and salts thereof), and the like. In particular, it is not limited to these, as long as it is a thermosetting catalyst for epoxy resins or oxetane compounds, or a catalyst that promotes the reaction of epoxy groups and / or oxetanyl groups with carboxyl groups, either alone or in combination of two or more. Can be used. Guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6-diamino S-triazine derivatives such as -S-triazine / isocyanuric acid adducts and 2,4-diamino-6-methacryloyloxyethyl-S-triazine / isocyanuric acid adducts can also be used. A compound that also functions in combination with a thermosetting catalyst.

The blending amount of these thermosetting catalysts is sufficient in the usual quantitative ratio, for example, preferably 100 parts by mass of the thermosetting component having a carboxyl group-containing oligomer or a plurality of cyclic (thio) ether groups in the molecule. The amount is 0.1 to 20 parts by mass, more preferably 0.5 to 15.0 parts by mass.

Furthermore, a colorant can be blended in the photocurable resin composition of the present invention. As the colorant, known colorants such as red, blue, green and yellow can be used, and any of pigments, dyes and pigments may be used. However, it is preferable not to contain a halogen from the viewpoint of reducing the environmental burden and affecting the human body.

Red colorant:
Examples of the red colorant include monoazo, diazo, azo lake, benzimidazolone, perylene, diketopyrrolopyrrole, condensed azo, anthraquinone, and quinacridone. -Indexes (CI; issued by The Society of Dyers and Colorists) are listed.
Monoazo: Pigment Red 1, 2, 3, 4, 5, 6, 8, 9, 12, 14, 15, 16, 17, 21, 22, 23, 31, 32, 112, 114, 146, 147, 151 , 170, 184, 187, 188, 193, 210, 245, 253, 258, 266, 267, 268, 269.
Disazo: Pigment Red 37, 38, 41.
Monoazo lakes: Pigment Red 48: 1, 48: 2, 48: 3, 48: 4, 49: 1, 49: 2, 50: 1, 52: 1, 52: 2, 53: 1, 53: 2, 57 : 1, 58: 4, 63: 1, 63: 2, 64: 1,68.
Benzimidazolone series: Pigment Red 171, Pigment Red 175, Pigment Red 176, Pigment Red 185, Pigment Red 208.
Perylene series: Solvent Red 135, Solvent Red 179, Pigment Red 123, Pigment Red 149, Pigment Red 166, Pigment Red 178, Pigment Red 179, Pigment Red 190, Pigment Red 194, Pigment Red 224.
Diketopyrrolopyrrole series: Pigment Red 254, Pigment Red 255, Pigment Red 264, Pigment Red 270, Pigment Red 272.
Condensed azo series: Pigment Red 220, Pigment Red 144, Pigment Red 166, Pigment Red 214, Pigment Red 220, Pigment Red 221 and Pigment Red 242.
Anthraquinone series: Pigment Red 168, Pigment Red 177, Pigment Red 216, Solvent Red 149, Solvent Red 150, Solvent Red 52, Solvent Red 207.
Kinacridone series: Pigment Red 122, Pigment Red 202, Pigment Red 206, Pigment Red 207, Pigment Red 209.

Blue colorant:
Blue colorants include phthalocyanine-based and anthraquinone-based pigments, and pigment-based compounds such as Pigment Blue 15 and Pigment Blue 15 are listed below. : 1, Pigment Blue 15: 2, Pigment Blue 15: 3, Pigment Blue 15: 4, Pigment Blue 15: 6, Pigment Blue 16, and Pigment Blue 60.
The dye systems include Solvent Blue 35, Solvent Blue 63, Solvent Blue 68, Solvent Blue 70, Solvent Blue 83, Solvent Blue 87, Solvent Blue 94, Solvent Blue 97, Solvent Blue 122, Solvent Blue 136, Solvent Blue 67, Solvent Blue 70 etc. can be used. In addition to the above, a metal-substituted or unsubstituted phthalocyanine compound can also be used.

Green colorant:
Similarly, green colorants include phthalocyanine, anthraquinone, and perylene. Specifically, Pigment Green 7, Pigment Green 36, Solvent Green 3, Solvent Green 5, Solvent Green 20, Solvent Green 28, etc. are used. be able to. In addition to the above, a metal-substituted or unsubstituted phthalocyanine compound can also be used.

Yellow colorant:
Examples of yellow colorants include monoazo, disazo, condensed azo, benzimidazolone, isoindolinone, anthraquinone, and the like.
Anthraquinone series: Solvent Yellow 163, Pigment Yellow 24, Pigment Yellow 108, Pigment Yellow 193, Pigment Yellow 147, Pigment Yellow 199, Pigment Yellow 202.
Isoindolinone type: Pigment Yellow 110, Pigment Yellow 109, Pigment Yellow 139, Pigment Yellow 179, Pigment Yellow 185.
Condensed azo series: Pigment Yellow 93, Pigment Yellow 94, Pigment Yellow 95, Pigment Yellow 128, Pigment Yellow 155, Pigment Yellow 166, Pigment Yellow 180.
Benzimidazolone series: Pigment Yellow 120, Pigment Yellow 151, Pigment Yellow 154, Pigment Yellow 156, Pigment Yellow 175, Pigment Yellow 181.
Monoazo: Pigment Yellow 1, 2, 3, 4, 5, 6, 9, 10, 12, 61, 62, 62: 1, 65, 73, 74, 75, 97, 100, 104, 105, 111, 116 , 167, 168, 169, 182, 183.
Disazo: Pigment Yellow 12, 13, 14, 16, 17, 55, 63, 81, 83, 87, 126, 127, 152, 170, 172, 174, 176, 188, 198.

In addition, a colorant such as purple, orange, brown, or black may be added for the purpose of adjusting the color tone.
Specifically, Pigment Violet 19, 23, 29, 32, 36, 38, 42, Solvent Violet 13, 36, CI Pigment Orange 1, CI Pigment Orange 5, CI Pigment Orange 13, CI Pigment Orange 14, CI CI Pigment Orange 16, CI Pigment Orange 17, CI Pigment Orange 24, CI Pigment Orange 34, CI Pigment Orange 36, CI Pigment Orange 38, CI Pigment Orange 40, CI Pigment Orange 43, CI Pigment Orange 46, CI Pigment Orange 49, CI CI Pigment Orange 51, CI Pigment Orange 61, CI Pigment Orange 63, CI Pigment Orange 64, CI Pigment Orange 71, CI Pigment Orange 73, CI Pigment Brown 23, CI Pigment Brown 25, CI Pigment Black 1, CI Pigment Black And the like.

Although the colorant as described above can be appropriately blended, it is preferably 10 parts by mass or less with respect to 100 parts by mass of the carboxyl group-containing oligomer or thermosetting component. More preferably, it is 0.1 to 5 parts by mass.

In the photocurable resin composition of the present invention, a compound having a plurality of ethylenically unsaturated groups in the molecule can be blended. The compound having a plurality of ethylenically unsaturated groups in the molecule used in the photocurable resin composition of the present invention is photocured by irradiation with active energy rays, and the photosensitive compound of the present invention or the carboxyl group-containing photosensitivity. The insoluble oligomer is insolubilized in the aqueous alkali solution or assists insolubilization. As such a compound, conventionally known polyester (meth) acrylate, polyether (meth) acrylate, urethane (meth) acrylate, carbonate (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate and the like can be used. Specifically, hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; glycol diacrylates such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol and propylene glycol; N, N-dimethyl Acrylamides such as acrylamide, N-methylolacrylamide, N, N-dimethylaminopropylacrylamide; N, N-dimethylaminoethyl acrylate Aminoalkyl acrylates such as N, N-dimethylaminopropyl acrylate; polyhydric alcohols such as hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, tris-hydroxyethylisocyanurate, or their ethylene oxide adducts, propylene oxide Polyvalent acrylates such as adducts or ε-caprolactone adducts; polyvalent acrylates such as phenoxy acrylate, bisphenol A diacrylate, and ethylene oxide adducts or propylene oxide adducts of these phenols; glycerin diglycidyl ether Glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl isocyanurate, etc. Polyvalent acrylates of sidyl ethers; other acrylates and melamine acrylates obtained by directly acrylated polyols such as polyether polyols, polycarbonate diols, hydroxyl-terminated polybutadienes, polyester polyols, or urethane acrylates via diisocyanates, and / or Examples include methacrylates corresponding to the acrylate.

Furthermore, an epoxy acrylate resin obtained by reacting acrylic acid with a polyfunctional epoxy resin such as a cresol novolac type epoxy resin, and further a hydroxy acrylate such as pentaerythritol triacrylate and a diisocyanate such as isophorone diisocyanate on the hydroxyl group of the epoxy acrylate resin. The epoxy urethane acrylate compound etc. which made the half urethane compound react are mentioned. Such an epoxy acrylate resin can improve the photocurability without deteriorating the touch drying property of the coating film.

Such compounds having a plurality of ethylenically unsaturated groups can be used singly or in combination of two or more. In particular, a compound having 4 to 6 ethylenically unsaturated groups in one molecule is preferable from the viewpoint of photoreactivity and resolution, and a compound having two ethylenically unsaturated groups in one molecule is used. And, it is preferable that the linear expansion coefficient of the cured product is lowered, and it has been found that the occurrence of cracks during the thermal cycle test is reduced.

The compounding amount of the compound having a plurality of ethylenically unsaturated groups in the molecule is preferably 5 to 100 parts by mass with respect to 100 parts by mass of the carboxyl group-containing oligomer. When the blending amount is less than 5 parts by mass, photocurability is lowered, and pattern formation becomes difficult by alkali development after irradiation with active energy rays. On the other hand, when it exceeds 100 mass parts, the solubility with respect to dilute alkali aqueous solution falls, and a coating film becomes weak. More preferably, it is 1 to 70 parts by mass.

Furthermore, the photocurable resin composition of the present invention may use an organic solvent for the synthesis of the carboxyl group-containing oligomer and the preparation of the composition, or for adjusting the viscosity for application to a substrate or a carrier film. it can. Such organic solvents are used alone or as a mixture of two or more.

In the photocurable resin composition of the present invention, in order to prevent oxidation, (1) a radical scavenger that invalidates the generated radical or / and (2) the generated peroxide is decomposed into a harmless substance, Antioxidants such as peroxide decomposers that prevent the generation of new radicals can be added.

Furthermore, an ultraviolet absorber can be used in the photocurable resin composition of the present invention in addition to the antioxidant.
Examples of such ultraviolet absorbers include benzophenone derivatives, benzoate derivatives, benzotriazole derivatives, triazine derivatives, benzothiazole derivatives, cinnamate derivatives, anthranilate derivatives, dibenzoylmethane derivatives, and the like.

The photo-curable resin composition of the present invention may further include a known thickener such as a known thermal polymerization inhibitor, fine silica, organic bentonite, and montmorillonite, a silicone-based, a fluorine-based, a polymer-based, etc., if necessary. Known additives such as antifoaming agents and / or leveling agents, imidazole-based, thiazole-based, triazole-based silane coupling agents, antioxidants, rust inhibitors, and the like can be blended.

In the photocurable resin composition of the present invention, an adhesion promoter can be used in order to improve the adhesion between layers or the adhesion between the formed resin insulation layer and the substrate. Examples of such adhesion promoters include, for example, benzimidazole, benzoxazole, benzothiazole, 3-morpholinomethyl-1-phenyl-triazole-2-thione, 5-amino-3-morpholinomethyl-thiazole-2-thione. , Triazole, tetrazole, benzotriazole, carboxybenzotriazole, amino group-containing benzotriazole, silane coupling agent and the like.

After the photocurable resin composition of the present invention configured as described above is prepared to a predetermined composition, it is adjusted to a viscosity suitable for a coating method with an organic solvent, for example, on a substrate, a dip coating method, a flow The coating method is a coating method, a roll coating method, a bar coater method, a screen printing method, a curtain coating method, or the like.
Then, the organic solvent contained in the composition is volatilized and dried (temporarily dried) at a temperature of about 60 to 100 ° C. to form a tack-free coating film (resin insulating layer). At this time, the volatile drying is performed by using a hot air circulation drying furnace, an IR furnace, a hot plate, a convection oven or the like (using a method having a heat source of an air heating method using steam in a countercurrent contact with hot air in the dryer) A method of spraying on a support).

Moreover, you may form a resin insulating layer by forming a dry film with a photocurable resin composition and bonding this on a base material.
The dry film has, for example, a structure in which a carrier film such as polyethylene terephthalate, a resin insulating layer such as a solder resist layer, and a peelable cover film used as necessary are laminated in this order.

The resin insulation layer is a layer obtained by applying and drying a photocurable resin composition on a carrier film or a cover film. For such a resin insulating layer, the photocurable resin composition of the present invention is uniformly applied to a carrier film with a thickness of 10 to 150 μm by a blade coater, a lip coater, a comma coater, a film coater, etc., and dried. Formed. And a dry film is formed by laminating | stacking a cover film further as needed. At this time, the carrier film may be laminated after the photocurable resin composition is applied to the cover film and dried.

As the carrier film, for example, a thermoplastic film such as a polyester film having a thickness of 2 to 150 μm is used.
As the cover film, a polyethylene film, a polypropylene film, or the like can be used, but a cover film having a smaller adhesive force than the solder resist layer is preferable.

If such a dry film is used and the cover film is used, after peeling off the cover film, the resin insulation layer and the base material are stacked and bonded together using a laminator or the like, so that the resin insulation layer is formed on the base material. It is formed. In addition, what is necessary is just to peel a carrier film before or after the exposure mentioned later.

At this time, as a base material on which a coating film is formed or a dry film is laminated, paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / non-woven cloth epoxy, glass cloth / paper epoxy, synthetic fiber epoxy, Made of materials such as copper clad laminates for high frequency circuits using fluorine, polyethylene, PPO, cyanate ester, etc., all grades (FR-4 etc.) copper clad laminates, other polyimide films, PET films, glass A substrate, a ceramic substrate, a wafer plate, etc. can be mentioned.

Further, the pattern is exposed by an active energy beam or directly by a laser direct exposure machine through a photomask having a pattern formed by a contact method (or non-contact method). In the coating film, the exposed portion (the portion irradiated by the active energy ray) is cured.
As an exposure machine used for active energy ray irradiation, a direct drawing device (for example, a laser direct imaging device that draws an image directly with a laser using CAD data from a computer), an exposure device equipped with a metal halide lamp, and an (ultra) high-pressure mercury lamp It is possible to use an exposure machine mounted, an exposure machine equipped with a mercury short arc lamp, or a direct drawing apparatus using an ultraviolet lamp such as a (super) high pressure mercury lamp.

As the active energy ray, it is preferable to use laser light having a maximum wavelength in the range of 350 to 410 nm. By setting the maximum wavelength within this range, radicals can be efficiently generated from the photopolymerization initiator. If a laser beam in this range is used, either a gas laser or a solid laser may be used. The amount of exposure varies depending on the film thickness and the like, but can generally be in the range of 5 to 500 mJ / cm ² , preferably 10 to 300 mJ / cm ² .

As the direct drawing apparatus, for example, those manufactured by Nippon Orbotech, Pentax, etc. can be used, and any apparatus that oscillates laser light having a maximum wavelength of 350 to 410 nm may be used. .

Then, by exposing in this way, the exposed portion (the portion irradiated with the active energy ray) is cured, and the unexposed portion is developed with a dilute alkaline aqueous solution (for example, 0.3 to 3 wt% sodium carbonate aqueous solution). Thus, a cured product (pattern) is formed.
At this time, as a developing method, a dipping method, a shower method, a spray method, a brush method, or the like can be used. Further, as the developer, an alkaline aqueous solution such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines and the like can be used.

Further, when a thermosetting component is added, for example, by heating to a temperature of about 140 to 180 ° C. and thermosetting, the carboxyl group of the carboxyl group-containing oligomer and, for example, a plurality of cyclic ether groups and / or cyclic groups in the molecule A thermosetting component having a thioether group reacts to form a cured product (pattern) excellent in various properties such as heat resistance, chemical resistance, moisture absorption resistance, adhesion, and electrical characteristics.

Thus, in the photocurable resin composition, by containing a carboxyl group-containing oligomer, a polymer binder having a molecular weight larger than that of the carboxyl group-containing oligomer, a photopolymerization initiator, a photopolymerizable monomer, a filler, In the cured product, it is possible to obtain reliability such as heat resistance required when used for electronic parts and the like, and heat cycle resistance without impairing migration resistance characteristics. And it becomes possible by using such hardened | cured material for a printed wiring board etc. to obtain high reliability.

Hereinafter, the present invention will be described in detail with reference to examples and comparative examples, but the present invention is not limited to the following examples. In the following, “parts” and “%” are based on mass unless otherwise specified.

Synthesis example 1
A novolac-type cresol resin (trade name “Shonol CRG951”, manufactured by Showa Polymer Co., Ltd., OH equivalent: 119.4) is added to an autoclave equipped with a thermometer, a nitrogen introduction device / alkylene oxide introduction device, and a stirring device. 4 parts, 1.19 parts of potassium hydroxide and 119.4 parts of toluene were charged, the system was purged with nitrogen while stirring, and the temperature was raised. Next, 63.8 parts of propylene oxide was gradually added dropwise and reacted at 125 to 132 ° C. and 0 to 4.8 kg / cm ² for 16 hours. Thereafter, the reaction solution was cooled to room temperature, and 1.56 parts of 89% phosphoric acid was added to and mixed with the reaction solution to neutralize potassium hydroxide. The nonvolatile content was 62.1% and the hydroxyl value was 182.2 g / eq. A novolak-type cresol resin propylene oxide reaction solution was obtained. This was an average of 1.08 moles of alkylene oxide added per equivalent of phenolic hydroxyl group.
293.0 parts of an alkylene oxide reaction solution of the obtained novolak-type cresol resin, 43.2 parts of acrylic acid, 11.53 parts of methanesulfonic acid, 0.18 part of methylhydroquinone and 252.9 parts of toluene were mixed with a stirrer and a temperature. A reactor equipped with a meter and an air blowing tube was charged, air was blown at a rate of 10 ml / min, and the reaction was carried out at 110 ° C. for 12 hours while stirring. 12.6 parts of water was distilled from the water produced by the reaction as an azeotrope with toluene. Thereafter, the reaction solution was cooled to room temperature, neutralized with 35.35 parts of a 15% aqueous sodium hydroxide solution, and then washed with water. Thereafter, toluene was distilled off while substituting 118.1 parts of diethylene glycol monoethyl ether acetate with an evaporator to obtain a novolak acrylate resin solution. Next, 332.5 parts of the obtained novolak acrylate resin solution and 1.22 parts of triphenylphosphine were charged into a reactor equipped with a stirrer, a thermometer and an air blowing tube, and air was supplied at a rate of 10 ml / min. While blowing and stirring, 60.8 parts of tetrahydrophthalic anhydride was gradually added, reacted at 95 to 101 ° C. for 6 hours, cooled and taken out. Thus, a solution (hereinafter abbreviated as A-1) of a carboxyl group-containing photosensitive oligomer (Mw: 2650) having a non-volatile content of 65% and a solid acid value of 87.7 mgKOH / g was obtained.

Synthesis example 2
Put 330 parts of cresol novolac type epoxy resin (Epiclon N-695, manufactured by DIC Corporation, epoxy equivalent 220) in a flask equipped with a gas introduction tube, a stirrer, a condenser tube and a thermometer, and add 340 parts of carbitol acetate. In addition, the mixture was dissolved by heating, and 0.46 part of hydroquinone and 1.38 parts of triphenylphosphine were added. This mixture was heated to 95 to 105 ° C., 108 parts of acrylic acid was gradually added dropwise and reacted for 16 hours. The reaction product was cooled to 80 to 90 ° C., 68 parts of tetrahydrophthalic anhydride was added, reacted for 8 hours, and cooled. Thus, a solution (hereinafter abbreviated as A-4) of a carboxyl group-containing photosensitive oligomer (Mw: 9500) having a solid acid value of 50 mgKOH / g and a nonvolatile content of 60% was obtained.

Examples 1 to 16 and Comparative Examples 1 to 3
Using the resin solution of the above synthesis example, blended in the proportions (parts by mass) shown in Table 1 together with various components shown in Table 1 below, premixed with a stirrer, kneaded with a three-roll mill, and used for solder resist A photosensitive resin composition was prepared.

The meanings of the reference symbols in Table 1 are as follows.
* 1 ZFR-1124 (nonvolatile content: 65.0%, solid content acid value: 100 mgKOH / g, Mw: 11500, manufactured by Nippon Kayaku Co., Ltd.)
* 2 ZCR-1601H (nonvolatile content: 65.0%, solid content acid value: 100 mgKOH / g, Mw: 1730, manufactured by Nippon Kayaku Co., Ltd.)
* 3 Ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] 1,1- (o-acetyloxime) (BASF Japan)
* 4 Lucillin TPO (manufactured by BASF)
* 5 SG-2000 manufactured by Nippon Talc Co., Ltd. (refractive index: 1.57)
* 6 B-33 manufactured by Sakai Chemical Industry Co., Ltd. (refractive index: 1.64)
* 7 Showa Denko Co., Ltd. Hijilite H-42M (refractive index: 1.65)
* 8 Siritin (natural combination of plate-like kaolinite and spherical silica, refractive index: 1.57)
* 9 SO-E2 manufactured by Admatechs Co., Ltd. (refractive index: 1.45)
* 10 DHT-4A manufactured by Kyowa Chemical Industry Co., Ltd. (refractive index: 1.50)
* 11 YP-50 manufactured by Nippon Steel Chemical Co., Ltd. (phenoxy resin, Mw: approx. 70,000)
* 12 YP-50 carbitol acetate dissolved product manufactured by Nippon Steel Chemical Co., Ltd. (solid content 30%)
* 13 MAM-M51 manufactured by Arkema Co., Ltd. (ternary block copolymer: polymethyl methacrylate-polybutyl acrylate-polymethyl methacrylate, Mw: about 56,000)
* 14 MAM-M52 manufactured by Arkema Co., Ltd. (ternary block copolymer: polymethyl methacrylate-polybutyl acrylate-polymethyl methacrylate, Mw: about 96,000)
* 15 SBM-E41 manufactured by Arkema Co., Ltd. (ternary block copolymer: polystyrene-polybutadiene-polymethyl methacrylate, Mw: about 42,000)
* 16 CAP-482 (cellulose acetopropionate, Mw: about 75,000) manufactured by Eastman Chemical Co.
* 17 Byron 670 manufactured by Toyobo Co., Ltd. (amorphous polyester resin, Mn: about 30,000)
* 18 Bixylenol-type epoxy resin (Mitsubishi Chemical Corporation)
* 19 Bisphenol-type epoxy resin (manufactured by Nippon Steel Chemical Co., Ltd.)
* 20 CIPigment Blue 15: 3
* 21 CIPigment Yellow 147
* 22 Dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd.)

Characteristic test:
Each of the compositions of Examples and Comparative Examples was applied on the entire surface of a patterned copper foil substrate by screen printing, dried at 80 ° C. for 30 minutes, and allowed to cool to room temperature. Using this exposure apparatus equipped with a high-pressure mercury lamp on this substrate, the solder resist pattern is exposed at an optimum exposure amount, and developed with a 1 wt% sodium carbonate aqueous solution at 30 ° C. under a spray pressure of 0.2 MPa for 90 seconds. Obtained. This substrate was irradiated with ultraviolet rays under a condition of an integrated exposure amount of 1000 mJ / cm ^{2 in} a UV conveyor furnace, and then cured by heating at 160 ° C. for 60 minutes. The characteristics of the obtained printed circuit board (evaluation board) were evaluated as follows.

<Optimum exposure amount>
A circuit pattern substrate having a copper thickness of 35 μm was polished with buffalo, washed with water and dried, and then the compositions of the examples and comparative examples were applied to the entire surface by a screen printing method, and 30 ° C. in a hot air circulation drying oven at 80 ° C. Let dry for minutes. Thereafter, exposure is performed through a 41-step tablet of a stoker using an exposure apparatus (HMW-680-GW20) equipped with a metal halide lamp, and development (30 ° C., 0.2 MPa, 1 wt% Na ₂ CO ₃ aqueous solution) is performed at 60 ° C. When the pattern of the step tablet remaining when it was performed in seconds was 7 steps, the optimum exposure amount was set.

<Applicability>
The entire surface of the patterned copper foil substrate was applied by screen printing, and the printed state was confirmed. The judgment criteria are as follows.
(Double-circle): The film thickness of a resist ink is hold | maintained uniformly on a pattern.
○: Some unevenness occurs on the pattern, but the film thickness of the resist ink is maintained.
X: The ink on a pattern becomes thin.

<Electroless gold plating resistance>
Using a commercially available electroless nickel plating bath and electroless gold plating bath, plating is performed under the conditions of nickel 0.5 μm and gold 0.03 μm, and the presence of peeling of the resist layer and the penetration of the plating solution by tape peeling Then, the presence or absence of the resist layer was evaluated by tape peeling. The judgment criteria are as follows.
A: No soaking or peeling is observed.
○: Slight penetration is confirmed after plating, but does not peel off after tape peeling.
Δ: Slight penetration after plating and peeling after tape peel.
X: There is peeling after plating.

<PCT resistance>
It was placed in a high-pressure, high-temperature and high-humidity tank at 121 ° C., 2 atm and 100% humidity for 168 hours, and the change in state of the cured coating film was evaluated according to the following evaluation criteria.
A: No noticeable swelling or discoloration.
○: There is a minute bulge and no discoloration.
X: Remarkable swelling and discoloration.

<Crack resistance>
Thermal history was added for 30 minutes at −55 ° C. and 30 minutes at 125 ° C., and after 1000 cycles, the samples were observed with an optical microscope. The judgment criteria are as follows.
(Double-circle): There is no crack generation.
○: Cracks are generated.
X: Crack generation is remarkable.

<Resolution>
Each photocurable thermosetting resin composition of an Example and a comparative example was apply | coated by the screen printing method to the board | substrate with which plating copper was formed, and was dried for 30 minutes with a 80 degreeC hot-air circulation type drying furnace. After drying, exposure was performed using an exposure apparatus equipped with a high-pressure mercury lamp (short arc lamp). The exposure pattern used was a glass dry plate on which a circle with an opening of 50/60/70/80/90/100 μm was drawn. The active energy ray was irradiated so that the exposure amount became the optimal exposure amount of the photosensitive resin composition. After the exposure, a 1 wt% sodium carbonate aqueous solution at 30 ° C. was developed for 90 seconds under a spray pressure of 0.2 MPa to obtain a resist pattern. This substrate was irradiated with ultraviolet rays under a condition of an integrated exposure amount of 1000 mJ / cm ^{2 in} a UV conveyor furnace, and then cured by heating at 160 ° C. for 60 minutes.
The minimum opening of the cured coating film of the obtained photosensitive resin composition for solder resist was determined using an optical microscope adjusted to 200 times. The judgment criteria are as follows.
A: Less than 60 μm.
○: 60 μm or more and less than 80 μm.
Δ: 80 μm or more and less than 100 μm.
X: 100 μm or more.

<Linear expansion coefficient>
A tensile test was performed on a cured coating film having a size of 3 mm × 10 mm in a temperature range of 0 ° C. to 260 ° C. at a constant temperature increase rate while applying a load of 10 g with TMA6100 manufactured by Seiko Instruments Inc. The linear expansion coefficient was calculated from the amount of elongation of the cured coating film with respect to temperature.
The results of the above tests are summarized in Table 2.

As shown in Table 2 above, in each of the examples using the photocurable resin composition of the present invention, all of applicability, electroless gold plating resistance, PCT resistance, and crack resistance were excellent. On the other hand, in the case of the comparative example 1 which did not mix | blend a polymer binder, it became a dilatancy state remarkably and it was difficult to apply | coat. Furthermore, the resolution was inferior. On the other hand, in the case of Comparative Example 2 in which a polymer binder was blended but no filler was blended, there was no problem in applicability and resolution, but the linear expansion coefficient could not be lowered and crack resistance was poor. Moreover, it became easy to permeate | transmit water, such as a plating solution, by not containing a filler, and was inferior to electroless gold-plating tolerance and PCT tolerance. Moreover, also in the case of the comparative example 3 with few compounding quantities of a filler, a linear expansion coefficient was not able to be made low enough, but there existed a problem in crack tolerance.

By using the photo-curable resin composition of the present invention, even if a large amount of filler is blended, it is easy to handle as a solder resist, and it is possible to suppress the generation and peeling of the solder resist cracks that occur during the cooling and heating cycle. And a solder resist such as a flexible wiring board, an interlayer insulating material of a multilayer wiring board, and the like, particularly for forming a solder resist for a semiconductor package.

Claims (10)

1. A composition comprising a carboxyl group-containing oligomer, a polymer binder having a molecular weight larger than that of the carboxyl group-containing oligomer, a photopolymerization initiator, a photopolymerizable monomer, and a filler, wherein the filler content is the entire nonvolatile component of the composition A photocurable resin composition developable with an alkaline solution, characterized in that the amount is 30 to 60% by mass of the amount.
2. The photocurable resin composition according to claim 1, wherein the polymer binder is a thermoplastic resin.
3. 3. The photocurable resin composition according to claim 2, wherein the thermoplastic resin has a solid content of 10 to 50 wt% in a state dissolved in the same solvent.
4. The photocurable resin composition according to claim 1, wherein the filler contains Ba, Mg, and / or Al.
5. A dry film obtained by coating and drying the photocurable resin composition according to any one of claims 1 to 4 on a carrier film.
6. The dry film comprises a plurality of dry layers of a photocurable resin composition, and at least one layer is formed from the photocurable resin composition according to any one of claims 1 to 4. The dry film according to claim 5.
7. A cured product obtained by applying the photocurable resin composition according to any one of claims 1 to 4 to a substrate and photocuring it by irradiation with active energy rays.
8. 5. A pattern of a cured product obtained by applying the photocurable resin composition according to any one of claims 1 to 4 to a substrate, drying and photocuring by irradiation with an active energy ray. Printed wiring board.
9. A cured product obtained by laminating the dry film according to claim 5 or 6 on a substrate and photocuring it by irradiation with active energy rays.
10. 7. A printed wiring board comprising a pattern of a cured product obtained by laminating the dry film according to claim 5 or 6 on a substrate and photocuring by irradiation with active energy rays.